
    /**  
    * @Title: SqlHelper.java
    * @Package com.third.mybatis.util
    * @Description: 
    * @author likai
    * @date 2017年5月18日
    * @version V1.0  
    */
    
package com.utils.mybatis;


import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMapping;
import org.apache.ibatis.mapping.ParameterMode;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.SystemMetaObject;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.type.JdbcType;
import org.apache.ibatis.type.TypeHandlerRegistry;

import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**

 * Mybatis - 获取Mybatis执行的sql语句工具

 *
 */
@SuppressWarnings("rawtypes")
public class SqlHelperUtil {


    /**

     * 通过接口获取sql

     *

     * @param mapper接口对象

     * @param methodName接口方法

     * @param args接口参数

     * @return

     */
	public static String getMapperSql(Object mapper, String methodName, Object... args) {
        MetaObject metaObject = SystemMetaObject.forObject(mapper);
        SqlSessionFactory session = (SqlSessionFactory) metaObject.getValue("h.SqlSessionFactory");
        Class mapperInterface = (Class) metaObject.getValue("h.mapperInterface");
        String fullMethodName = mapperInterface.getCanonicalName() + "." + methodName;
        if (args == null || args.length == 0) {
            return getNamespaceSql(session, fullMethodName, null);
        } else {
            return getMapperSql(session, mapperInterface, methodName, args);
        }
    }

    /**

     * 通过Mapper方法名获取sql

     *

     * @param session

     * @param fullMapperMethodName接口完整包路径方法名

     * @param args

     * @return

     */
    public static String getMapperSql(SqlSessionFactory session, String fullMapperMethodName, Object... args) {
        if (args == null || args.length == 0) {
            return getNamespaceSql(session, fullMapperMethodName, null);
        }
        String methodName = fullMapperMethodName.substring(fullMapperMethodName.lastIndexOf('.') + 1);
        Class mapperInterface = null;
        try {
            mapperInterface = Class.forName(fullMapperMethodName.substring(0, fullMapperMethodName.lastIndexOf('.')));
            return getMapperSql(session, mapperInterface, methodName, args);
        } catch (ClassNotFoundException e) {
            throw new IllegalArgumentException("参数" + fullMapperMethodName + "无效！");
        }
    }

    /**

     * 通过Mapper接口和方法名

     *

     * @param session

     * @param mapperInterface

     * @param methodName

     * @param args

     * @return

     */
    @SuppressWarnings("unchecked")
	public static String getMapperSql(SqlSessionFactory session, Class mapperInterface, String methodName, Object... args) {
        String fullMapperMethodName = mapperInterface.getCanonicalName() + "." + methodName;
        if (args == null || args.length == 0) {
            return getNamespaceSql(session, fullMapperMethodName, null);
        }
        Method method = getDeclaredMethods(mapperInterface, methodName);
        Map params = new HashMap();
        final Class<?>[] argTypes = method.getParameterTypes();
        for (int i = 0; i < argTypes.length; i++) {
            if (!RowBounds.class.isAssignableFrom(argTypes[i]) && !ResultHandler.class.isAssignableFrom(argTypes[i])) {
                String paramName = "param" + String.valueOf(params.size() + 1);
                paramName = getParamNameFromAnnotation(method, i, paramName);
                params.put(paramName, i >= args.length ? null : args[i]);
            }
        }
        if (args != null && args.length == 1) {
            Object _params = wrapCollection(args[0]);
            if (_params instanceof Map) {
                params.putAll((Map) _params);
            }
        }
        return getNamespaceSql(session, fullMapperMethodName, params);
    }


    /**

     * 通过命名空间方式获取sql

     *

     * @param session

     * @param namespace

     * @return

     */
    public static String getNamespaceSql(SqlSessionFactory session, String namespace) {
        return getNamespaceSql(session, namespace, null);
    }

    /**

     * 通过命名空间方式获取sql

     *

     * @param session

     * @param namespace

     * @param params

     * @return

     */
    public static String getNamespaceSql(SqlSessionFactory session, String namespace, Object params) {
        params = wrapCollection(params);
        Configuration configuration = session.getConfiguration();
        MappedStatement mappedStatement = configuration.getMappedStatement(namespace);
        TypeHandlerRegistry typeHandlerRegistry = mappedStatement.getConfiguration().getTypeHandlerRegistry();
        BoundSql boundSql = mappedStatement.getBoundSql(params);
        List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
        String sql = boundSql.getSql();
        if (parameterMappings != null) {
            for (int i = 0; i < parameterMappings.size(); i++) {
                ParameterMapping parameterMapping = parameterMappings.get(i);
                if (parameterMapping.getMode() != ParameterMode.OUT) {
                    Object value;
                    String propertyName = parameterMapping.getProperty();
                    if (boundSql.hasAdditionalParameter(propertyName)) {
                        value = boundSql.getAdditionalParameter(propertyName);
                    } else if (params == null) {
                        value = null;
                    } else if (typeHandlerRegistry.hasTypeHandler(params.getClass())) {
                        value = params;
                    } else {
                        MetaObject metaObject = configuration.newMetaObject(params);
                        value = metaObject.getValue(propertyName);
                    }
                    JdbcType jdbcType = parameterMapping.getJdbcType();
                    if (value == null && jdbcType == null) jdbcType = configuration.getJdbcTypeForNull();
                    sql = replaceParameter(sql, value, jdbcType, parameterMapping.getJavaType());
                }
            }
        }
        return sql;
    }

    /**

     * 根据类型替换参数

     * 仅作为数字和字符串两种类型进行处理，需要特殊处理的可以继续完善这里

     *

     * @param sql

     * @param value

     * @param jdbcType

     * @param javaType

     * @return

     */
    private static String replaceParameter(String sql, Object value, JdbcType jdbcType, Class javaType) {
        String strValue = String.valueOf(value);
        if (jdbcType != null) {
            switch (jdbcType) {
                //数字

                case BIT:
                case TINYINT:
                case SMALLINT:
                case INTEGER:
                case BIGINT:
                case FLOAT:
                case REAL:
                case DOUBLE:
                case NUMERIC:
                case DECIMAL:
                    break;
                //日期

                case DATE:
                case TIME:
                case TIMESTAMP:
                    //其他，包含字符串和其他特殊类型

                default:
                    strValue = "'" + strValue + "'";


            }
        } else if (Number.class.isAssignableFrom(javaType)) {
            //不加单引号

        } else {
            strValue = "'" + strValue + "'";
        }
        return sql.replaceFirst("\\?", strValue);
    }

    /**

     * 获取指定的方法

     *

     * @param clazz

     * @param methodName

     * @return

     */
    private static Method getDeclaredMethods(Class clazz, String methodName) {
        Method[] methods = clazz.getDeclaredMethods();
        for (Method method : methods) {
            if (method.getName().equals(methodName)) {
                return method;
            }
        }
        throw new IllegalArgumentException("方法" + methodName + "不存在！");
    }

    /**

     * 获取参数注解名

     *

     * @param method

     * @param i

     * @param paramName

     * @return

     */
    private static String getParamNameFromAnnotation(Method method, int i, String paramName) {
        final Object[] paramAnnos = method.getParameterAnnotations()[i];
        for (Object paramAnno : paramAnnos) {
            if (paramAnno instanceof Param) {
                paramName = ((Param) paramAnno).value();
            }
        }
        return paramName;
    }

    /**

     * 简单包装参数

     *

     * @param object

     * @return

     */
    private static Object wrapCollection(final Object object) {
        if (object instanceof List) {
            Map<String, Object> map = new HashMap<String, Object>();
            map.put("list", object);
            return map;
        } else if (object != null && object.getClass().isArray()) {
            Map<String, Object> map = new HashMap<String, Object>();
            map.put("array", object);
            return map;
        }
        return object;
    }
    
    
/*    public void test() {  
    	SqlSessionFactory sqlSession ;  
        try {  
            CountryMapper countryMapper = sqlSession.getMapper(CountryMapper.class);  
      
            System.out.println(  
                    SqlHelper.getNamespaceSql(  
                            sqlSession,  
                            "com.github.pagehelper.mapper.CountryMapper.selectIf2ListAndOrder"));  
      
            System.out.println(  
                    SqlHelper.getMapperSql(  
                            countryMapper,  
                            "selectIf2ListAndOrder",  
                            Arrays.asList(1, 2)));  
      
            System.out.println(  
                    SqlHelper.getMapperSql(  
                            sqlSession,  
                            "com.github.pagehelper.mapper.CountryMapper.selectAll"));  
      
            System.out.println(  
                    SqlHelper.getMapperSql(  
                            sqlSession,  
                            "com.github.pagehelper.mapper.CountryMapper.selectIf2ListAndOrder",  
                            Arrays.asList(1, 2),  
                            Arrays.asList(3, 4),  
                            "id"));  
        } finally {  
            sqlSession.close();  
        }  
    }  */
}